HEALTH, SAFETY & ENVIRONMENT

For

INFRASTRUCTURE INDUSTRY

ASSIGNMENT

TOPIC: HSE ASPECTS IN CONSTRUCTION

OF BURJ KHALIFA, DUBAI

Submitted by:-

Roubal Khorana - R580213013

ShekharDorle-R580213016

Sombwit Kabasi R580213019

MBA IFM (SEM IV)

Submitted to:-

Dr. Nihal Anwar Siddiqui

INTRODUCTION

Dubi, UE, erected the most colossl structure the world hs ever seen, the Burj Dubi.The skyscrper stnds over 800 m tll, comfortbly winning distinctions the worlds tllest, free-stnding mn-mde structure. With unprecedented heights, the Burj Dubi is trulyimpressive. The Burj Dubi fetures some of the most cretive nd innovtive rchitecture nd ccommodtionsever seen. Some of these re designed to improve sfety, prticulrly fire sfety. With building tht tll,firehouses will not be ble to rech mybe 10 - 15% of the floors. Necessities of fire sfety include the bilityfor public servnts to rech ny height of the building quickly, for occupnts to evcute efficiently nd sfely,to control the spred of the fire nd, more importntly, smoke. The Burj Dubi uses n intricte systemofelevtors to id with fire sfety. Some fster, lrger service elevtors cn override loclelevtors nd work totrnsport crowds. Other lifebot elevtors cn ctully be mnully operted on emergency power using cmernd joystick. The Burj Dubi lso is equipped with res of refuge pproximtely every 25 floors.These re designed for sfety, including LCD monitors for instruction, fire resistnt construction, ndconnection to multiple stircses. The buildings ventiltion is lso revolutionry, nd helps immensely withthe issue of smoke nd other toxins.Wind stbility is the other gret concern with structure of this mgnitude. The design is expected tomintin comfortble fctor of sfety t ll times, even under lrge wind lods, to void ctstrophic filure.The entireBurj Dubi design bodes well for wind sfety. The structure fetures Y-shped, rigid cross-sectionwhich is esy to construct. The skyscrper lso is tpered, mening the wings recess s the floorsincrese. This confuses the wind nd countercts the formtion of vortices, gretly reducing wind lod.

Finlly, the concrete mixtures re custom, nd re impressive not only in their strength but in theirconstructbility t high heights. The steel reinforcement is the lst, nd possibly most importnt, piece thtcontributes to the towers structurl integrity. It is found tht the building is remrkbly sturdy, both in torsionnd under lterl stressing. This is supported by wind tunnel testing. The combintion of these mitigtion techniques for both fire nd wind in the record-holdingskyscrper mke the building very sfe. The building is fully equipped nd redy to hndlemost crisis situtions, provided tht stff nd crisis mngement personnel re prepred to follow the plns.The building llows for open communiction in crisis situtions, long with series of stirwells, emergencyelevtors, nd refuge res to void trpping ny occupnts. The equipped fetures of the tower lso llow forgret control over the fire nd the smoke toxins it produces.In ddition, the building is remrkbly stble. The chosen design never llows the wind to congregtend s such never experiences whole lot of force from fluid sources. Concrete reinforcement nd verystrong foundtion further increse structurl integrity. Finlly, the building gets exponentilly lighter s itscends its 162 floors; this mkes the weight t the top much lighter thn the weight t the bottom. There is noperfect wy of predicting wht the building will undergo in its lifespn. However,the Burj Dubi ppers prepred to tke

the crown s the tllest building in the world, nd should hold s nicon of humn chievement for mny yers.

DESIGN

The gol of the Burj Dubi design tem ws to develop model tht would not only be stble nd self-sustining t record breking heights, but lso esy to construct nd mintin. They lso wished for the utmost stisfction to the future occupnts. First nd foremost, they need the occupnts to feel sfe while enjoying ll of the services of the unsurpssed edifice.

The overll composition is verticl object reduced nd trnsformed by spirl reduction of brnch lengths until it reches its centrl shft t which point the shft peels wy to revel triptych configurtion tht erodes in spirl mnner until there is single spire. The finl cross-section is sort of inverted tringle. The three wings of the building stretch out from centrl core. This mkes for very rigid structure under torsion,s well s ensuring mximum visibility long the wings. The building is tpered, mening tht the wings recess s they pproch the top. This cretes n exponentil shpe tht not only emphsizes height, but hs collection of other benefits described lter. Figure 1 depicts the profile nd section views of the building. The buttress core is six sided, nd cts s the spire of the skyscrper. Concrete used for the core is super reinforced, nd rnges between 500 mm to 1300 mm thick. They core wlls re supported through series of 800mm to 1100mm deep reinforced concrete. Due to the fortitude, the core houses the

mjority of importnt menities, including the wter nd plumbing systems, electricl grids, nd elevtors.

Burj Dubi cross-section nd profile (http://www.worldrchitecturenews.com/news_imges/1000% 20Burj%20cross%20section.jpg)

CONSTRUCTION

Burj khlif construction time: 48 months. The originl construction progrm

ws very tight. To complete the project within 48 months, Smsung, Besix,

rbtechJoint Venture (SBJV) estblished the following strtegic pproch:

chieve three dy-cycle for structurl works.

Develop optimum trnsporttion systems with lrge cpcity high

speed equipment.

Utilize optimum formwork system to ccommodte vrious building

shpes long the building height.

The tower consists of more thn 160 floors & to be completed within very

tight schedule hence, the following key construction technologies were

incorported to chieve the 3-dy cycle set for the concrete works:

uto climbing formwork system (CS).

Rebr pre-fbriction.

High performnce concrete suitble for providing high strength, high

durbility requirement, high modulus, nd pumping.

dvnced concrete pumping technology.

Simple drop hed formwork system tht cn be dismntled nd

ssembled quickly with minimum lbor requirement.

Column/Wll proceeding method, prt of CS formwork system.

The process of selecting the right equipment to ensure delivery of mterils

nd workers effectively nd efficiently is nrt in its own right. Selecting the

optiml equipment nd verticl trnsporttion system for construction

requires ongoing nlysis nd constntmodifictions due to the dynmic

nture of the project during its construction life. Summry of the equipment

used Tower crnesTower min hoistsConcrete pumping equipment. The Burj

Khlif project is nother step forwrd in meeting the technologicl

chllenges of future construction.

HSE spects of Construction, Design nd Mngement (CDM) of Burj Khlif HSEs Dos nd Don'ts for Designers

Dos

To eliminte hzrds where fesible

To reduce risks from those hzrds tht cnnot be eliminted

To provide informtion on residul risks if they re significnt nd in order to dischrge these duties competent designer will need some knowledge nd experience of the construction process. For instnce:

To know wht the potentil hzrds will be during the construction, mintennce, clening nd dismntling of your design.

To stisfy themselves tht there is t lest one sfe wy of constructing their design.

Donts

CDM didnt require designers to

To stifle their cretivity, limit their design freedom or plce sfety bove esthetics

The elimintion of ttrctive feturessuch s tri;

Choose the sfest form of construction

Hve detiled knowledge of the construction process, or to specify stndrd construction processes or precutionry mesures to the contrctor;

Tke into ccount unforeseeble hzrds; designers to exercise ny helth nd sfety mngement functions over contrctors or sub-contrct designers

Designer Guidnce Design Risk ssessment Documenttion

In ccordnce with the CDM Regultions it is preferred to include ll significnt risk nlysis on drwings rther thn on written or numericl Design Hzrd nd Risk ssessment documents. This is to encourge visul nlysis nd recording of significnt construction nd mintennce

Significnt hzrds nd risks cn be hidden in the bureucrcy of project cusing them to be overlooked during design, pricing, construction nd mintennce stges of project

Project drwings to be nnotted in simple grphic mnner with key for further detil or reference.

ll relevnt risk informtion is collted in one plce with ll ssocited complexity visully pprent to ll prticipnts in the risk reduction process.

Designer friendly techniques were used to ensure ll significnt nd unusul or specific hidden issues were not missed even during design chnges.

Designer Guidnce Stndrd Sfety Symbols for Design Drwings

Contrctor Guidnce Site Drwing Sfety Symbols & Signge

Site Hzrd nlysis to fcilitte Initil Design & Construction Phse Decisions

To find the best building loction on the site, from the site nlysis, nd the optimum footprint, orienttion, size, scle, geometry nd sculpturl form?

Hzrdous locl gs instlltions, rilwy structures, trcks, viducts, rods, etc. below ground services, tunnels nd foundtions, retined structures etc

Drwings were produced tht show proximity to the gsholders nd rilwy viduct. Shows how close structure, temporry works, scffolding, hordings , welfre fcilities, etc. cn be built to the rilwy

Sfe theoreticl mximum building envelope ws greed erly together with sfe site set up principles voiding lter costs nd chnges eg. Rods, ccess etc

Site nlysis Underground Services for Initil Design nd Construction Phse

The identifiction nd loction of existing underground services prior to the positioning of future structures on site to minimise the need for

excvtions.

Electricl services nd gs supplies re potentilly highly hzrdous with the bility to cuse deth nd injury if ccidentlly struck during the construction phse, nd ll excvtions pose potentil risks.

Designer clerly identified hzrdous underground services on the drwings nd showed other services such s wter, fibre optics nd dringe

The sub-scn survey costs were significntly outweighed by the benefit of voiding delys, diversions or bridging. Site sfety is enhnced nd costs reduced through the elimintion of erthworks.

Site Contmintion - sbestos Survey Informtion on design drwings

To void exposure to free sbestos fibers of designers(on site visits) surveyors, site opertives, visitors, neighbors, nd users by designer intervention.

Fibers relesed during construction ctivities. This is often due to indequtely detiled surveys nd lck of understnding of how to interpret the sbestos Report.

nd site nd provision of ccurte sbestos survey drwings nd report to design tem. Key issues re loctions of sbestos contining mterils (CMs) nd res inccessible to survey which must be ssumed to contin sbestos, to be highlighted on drwings. Designer to dvise client to remove sbestos but if too expensive or imprcticble the designer must void it by designing round the res concerned or by encpsulting the CMs nd recording its residul presence on site in the H&S Pln nd on record drwings.

Reduction in likelihood of sbestos exposure before, during nd fter, nd in future construction works.

Detil Design - highlighting residul construction risks in the design

Highlighting significnt residul risks hidden or outside of competent

contrctors norml experience.

If these risks re not identified pre-tender it is possible tht the contrctor will under-estimte the cost nd detils of the temporry works solution for sfe construction.

Simple drwing nd survey nnottion techniques showing existing fetures, new proposls nd possible temporry works solution with commonly recognized symbols.

Simple identifiction on project drwings or surveys tht cn be used t pricing stges. These cn lso identify key issues for construction workers on site irrespective of lnguge nd eductionl difficulties.

Tender / Contrct Stge Design Temporry Fll Protection Issues

To lert the contrctors temporry works designers to unprotected slb nd roof edges where the designer could insert temporry protection works ides insted of trditionl perimeter scffolding system.

Flls from height during construction rther thn during future mintennce.

Designers to highlight typicl roof edges nd slb edges which need to be considered by contrctors whilst pricing for temporry works. Project drwings cn be used for site risk identifiction to ll contrcting stff irrespective of lnguge nd bility to understnd drwings.

Enbles contrctor to identify key sfety issues tht he needs to respond to by trditionl methods eg. Full scffolding. Or by mens of proprietry edge gurding methods to which designers cn contribute eg. Sockets in slbs, fixing points in steel, etc.

Guidnce- Detiled Design- Roof-lights nd frgile roofing mterils

Roof-lights nd frgile roofing mterils re economic, sustinble nd estheticlly desirble fetures which should not be eliminted from design projects purely for resons of sfety.

Flls through frgile roofing mterils re sttisticlly high nd often highly injurious or ftl

Construction Phse -Importnt to identify existing nd new frgile roof lights nd other frgile roofing mterils on drwings s method of informing the contrctor to control the risk of flls through these mterils during construction. Contrctors to recommend methods of temporry protection in tender or construction phse pln proposls to show their response.

dditionl protection mesures re required for the longer term in use condition such s metl rilings, brriers, wire mesh or non - frgile wlk on type roof lights. void in-plne roof-lights or sheeting.

Nturl dylighting is humn right nd engenders helthy nd sustinble environments

Initil Design- Roof ccess - Permnent Fll Prevention Methods

Roof ccess fll prevention methods proportionte to the frequency of ccess requirements for mintennce ctivities whilst considering the esthetic nd cost considertions.

Flls from height by plnt mintennce opertives or roof workers. ccess is unlikely to be entirely eliminted on ny roof due to inspections, clernce of rinwter outlets, etc.

Collective protection mesures should be selected in preference to other methods of protection, especilly in res requiring plnt mintennce on frequent bsis.

Where other fctors prevent the ddition of roof edge prpets, blustrding or rilings, mn sfe type fll restrint systems my be pproprite, set bck from roof perimeters.

Fll rrest methods using mn sfe systems re the lest cceptble option nd re only workble if fll recovery nd rescue systems re in plce. Consider dequte mens of sfe ccess to roof level for opertives with tools nd kit.

Fcilities mngers, mintennce opertives nd inspection stff cn mke low frequency visits eg. for rinwter outlet clernce if properly plnned mesures re in plce.

Elevtor Systems The Tower of Dubi plns to yet gin impress the world with itsmneuverbility. n intrictesystem of elevtors is the primry mode of verticl trnsporttion. The min considertion with this is themixed-use of the building. lso, ccording to Weismntle (2007), [the Burj Dubi] is so tll tht currentelevtor technology would not permit single elevtor to trvel the entire height of the building. This mens the Burj Dubi design tem needed to design n efficient trnsfer system, using locl nd shuttle elevtors. This is nlogous to commuter trins used in mny big cities round the world. Themost effective wy to do this is by stcking locl pssenger nd service elevtors so they only servicepertinent floors; tll, fst shuttleelevtors re used to nvigte between sections. Current elevtor designrequires buffer zones to house mechnicl components of the elevtor systems. The Burj Dubihndles this by plcing mechnicl nd electricl service floors in between sections ccessed only bystirs, s shown in figure

Fire Sfety The first re of concern, nd perhps most evident, is the fire sfety of the BurjDubi. Therere mny considertions with this. Firstly, public servnts reble to quickly ccess ny level ofthe skyscrper. t the sme time, occupnts need to be informed of the sitution, understnd wht to do,nd be ble to evcute sfely nd in timely mnner if needed. Finlly, the design hs to be ble tohndle smoke, not only ventilting it quickly, but by not letting it spred to the rest of the structure.

Controlling the Fire

s with most buildings, the Burj Dubi is outfitted with nutomtic sprinklersystem; its mintsk is to control the spred of the fire. ssisting in fire sfety is the fire resistnt construction. Theskyscrpers composition protects surrounding floors, rest zones, mechnicl res, nd hzrdous resfrom the other res round it. Occupnts cn be confident tht fire will not spred significntly fr insideof the Burj Dubi. The fire itself is minly thret to the occupnts in the immedite vicinity; however lrger thret is the smoke nd toxic gses tht hve the potentil to spred to even remote res of thebuilding.

Ventiltion

The Burj Dubi is equipped with mny smoke resistnt fetures. Firstly, the building usespressurized exit stirs. There re lso exhust systems in plce, long with overll smoke resistntconstruction. ll of these fetures ct together nd re designed to operte utomticlly when firelrm is tripped either mnully or from the fire detection system. Ech floor is outfitted with smokecomprtment tht trps nd contins smoke. Finlly, smoke control pnel will be provided toemergency personnel. This will llow firefighters nd prmedics to mnully djust the smoke controlsystems t their discretions.

Mitigting the Stck Effect

There is nother fluids relted phenomenon tht needs to be ddressed, clled the stck effect.Sometimes clled the chimney effect, the stck effect is pressure driven, nd occurs becuse of thedifference in ir densities of the cool inside ir of the tower to the hot outside Dubi ir. This will tend topush the inside ir down the interior of the tower, which sufficed to sy cn be dngerous with smoke.

The Burj Dubi rchitects hve countercted this effect in numerous wys. Just few of the mny techniques re listed below:

Stirwells re not in continuous shft

Extr sets of doors were plced between resident towers, elevtor shfts, nd lobby res

Residentil doors hve djustble door bottom sels

Mjor ir systems in the tower hve vrious speeds; this llows them to rect in rnge ofpressure conditions

Outside ir intke nd exhust systems hve monitoring systems for dded control

The smoke exhust system doubles s pressure relief to void over-pressuriztion

Firefighter ccessibility It is importnt for emergency personnel (e.g. firefighters, prmedics, police) to be ble to ccess building quickly in the event of n emergency. Being record holder does not exclude the Burj Dubifrom this rule. In ddition, these personnel cnnot be expected to scle ll 162 floors through stirwells.This need gets bck to the elevtor systems. The tower hs service elevtors tht run higher thn loclpssenger elevtors. In fct, one of these service elevtors runs over 500 m, nd is the tllest elevtorshft in the world. These re very fst, nd re configured to override thelocl elevtors to llow for the quickest nd esiest trnsfers. The elevtors themselves re fire/smokeresistnt. With these, it mkes ccessing the building reltively pinless process.

Occupnt Evcution

Occupnt evcution is the concern of ny building; however, it poses specil chllenge giventhe height of the Burj Dubi. With the tremendous climb, residents will need informtion on thesitution, mechnicl ssistnce to speed the process, nd stirwells nd sfe zones in the event ofmechnicl filures. It is importnt to note tht most crises thebuilding will experience will not require full building evcution.However, when lives re t stke, it is still importnt to be suretht it is possible.

res of Refuge

The tower design includes strtegiclly plced res ofrefuge which llow for better controlled evcution. Represented in figure, the typicl re of refuge will hve fire rted exitstirs closed off by doors to counter the spred of smoke.Building employees will be trined to direct nd instructevcuees. lso, the res of refuge re designed to connect tovrious stirwells. This mens tht occupnts cn be directeddown the sfest pth, nd will lmost never be trpped. s usul,the res of refuge re encsed in fire resistnt concrete, re wellventilted, nd cn be lit by emergency lights.

Elevtor-ssistnce

Similr to the public servnts scling the building, theevcuees cnnot be expected to descend the building given itswesome height. For this, mechnicl ssistnce is in plce. Inthe core of the building, the tower hs lrge lifebot elevtors. These lifts re completely operble onemergency bck-up power, nd cn ccommodte crowds of people. The lifebot elevtors re especillyimportnt, becuse they encse the occupnts in fire-sfe elevtor. Perhps the most interesting feture of these elevtors is the mnul override. Indeed, these elevtors cn ctully be controlled throughcmers nd joystick by the Dubi Civil Defense. The cmers re lso outfitted with LED lights tollow security tems to illuminte nd inspect hoist equipment nd elevtor components. Engineers ofmultiple sources hve estimted the time reduction of stirs-only to stirs with lifebot ssistnce to bebout 46%. Finlly, these specil elevtors, designed by Rolf Jensen &ssocites, Inc., cn be rechedthrough remote udio system. This, in ddition to more methods described below, llow crisismngement tems to ssist nd instruct extremely effectively.

Communiction The Burj Dubi is outfitted with n emergency P.. system nd fire lrms. The system isdesigned for selective notifiction to specific zones, but cn rech the entire structure. Exit signge ndemergency lighting mke evcution esier, long with multiple stircses designed to not isolte nysingle one. The dvnced building communiction system is lso equipped with public ddress systemsnd LCD units instll in residence hlls, hotel rooms, nd res of refuge. The res of refuge describederlier re ment to be used for continuous instruction s well. ll of these enhnce life sfety throughcommuniction, nd effectively increse speed nd effectiveness of the Burj Dubi Crisis MngementSystem.

Wind Sfety With ny tll building, wind is of gret concern; it cts s ftigue loding nd ccounts for the mjority of torsion nd trnsverse stresses tht the building experiences. s such, considering the erodynmics of the structures shpe is extremely importnt erly in the design process. These considertions depend on mny fctors, including wind speed nd surfce re. However, ll structures need to meet the bsic requirements for stbility, strength, nd servicebility. One of the criticl phenomen tht ffects tll slender towers is vortex excittion, which cuses strong fluctution forces in the crosswind direction. This is probbly the min behvior tht distinguishes tll towers from mid-rise buildings. The min gol of the Burj Dubi design tem ws to reduce these vortices by confusing the wind. lso, they constructed the building with dvnced mteril reinforcement, so the building cn remin stble under loding, even under its immense weight.

Mitigtion

There hve been vrious wys tht tower designers hve delt with the issue of high winds. Some use supplementry dmpening systems, such s the TMD of Tipei 101. Others choose to utilize the wind to improve sustinbility. The Commerzbnk building in Frnkfurt, Germny uses the wind s nturl ventiltion. However the Burj Dubi is different. The buildings design is lmost entirely designed round combting the wind forces.

Rigid Design

One of the wys tht the Burj Dubi is ble to remin free stnding is becuse of its Y-shpe s described erlier. Tringles re very strong shpes; from ny ngle they re supported by ll edges (wings in the cse of the Burj Dubi). Using this ide, the rchitect drin Smith ws ble to design the skyscrper to foster constructbility, s well s mke the building extremely rigid under torsion.

Combined with the six-sided core nd the rest of the design described in sections 2.0-2.2, the Burj Dubi is resistive to lmost ny pplied forces.

Confusing the Wind

nother key design feture of the tremendous tower is its recessive, tpering cross section. There re mthemticl models tht describe vortex shedding. Vortex shedding hppens when fluid (in this cse ir) flows pst blunt objects nd essentilly cretes low-pressure vortices downstrem of the object. When this hppens, the object will tend to move towrd the low-pressure zone. In ddition, vortex shedding is oscilltory, nd s such hs frequency. If the oscilltory frequency of the vortices mtches the resonnce frequency of the building, the structures movement cn become errtic nd potentilly dngerous. Needless to sy, this is n importnt problem to ddress. drin Smith relized tht the frequency of vortex shedding vries with width. With constntly chnging width, vortices re constntly trying to shed t different frequencies. This cuses interference, which cuses confusion, which cuses cncelltion. This is the fundmentl ide behind the tpering of the Burj Dubi. s the building scends nd the jet strems get stronger, the Burj Dubi esily cuts through the breeze. In ssurnce to the mitigted wind effects, floors get lighter nd smller s they get higher in the sky. The wider, more supported foundtion could support swying top with reltive ese. This, from distributed lod stndpoint, llows the edifice to completely stnd lone with no cble supports. ll of this in turn mkes for structure tht is ingenious in its hndling of trnsverse nd torque lodings, nd theoreticlly very sfe. But no mtter how strong the design is, proper mteril selections need to be mde to ensure stbility nd sfety.

CONCLUSION

The Burj Dubi performs remrkbly well under wind forces. The buildings ingenious setbck spire design resists vortex shedding nd s such does not llow for the wind to coordinte on the wlls of the tower. lso, its rigid tringulr shpe nd buttress core llow the building to stnd freely. The in theory nd in wind testing, the Burj Dubi hs performed dmirbly. The concrete of the building is supported well by thick steel bems; testing shows it cn comfortbly hndle even the highest stresses the building will experience. Combined with n extremely strong foundtion, the edifice is remrkbly strong in torsion nd under lterl stressing. The structure will be more thn cpble of stnding strong even under in strong wind situtions.

The designers of the Tower of Dubi hve tken the sfety of future occupnts into gret considertion. Through the use of elevtors nd stircses, crisis mngement personnel cn esily ccess ny level of the building. In contrst, the innovtive mneuverbility lso llows for quick evcution, ll the while keeping communiction open nd the spred of smoke down.

In summtion, the Burj Dubi is very sfe building in regrds to fire nd wind. Future occupnts cn be confident tht the building is stble nd will hndle well in crisis situtions. The vrious systems in plce hve mde it so tht ny occupnt cn be reched in lmost every circumstnce, s well s escpe quickly to either n re of refuge or ll the wy out of the building. From my inspections, the Burj Dubiwill stnd s symbol of humn mbition nd intelligence for very long time. lthough the height of the building is remrkble, the rchitecturl stbility nd sfety is close, if not, just s impressive.